Bug 546349

Résumé:

SELinux is preventing /lib/ld-2.11.so from making the program stack executable.

Description détaillée:

The ld-linux.so.2 application attempted to make its stack executable. This is a
potential security problem. This should never ever be necessary. Stack memory is
not executable on most OSes these days and this will not change. Executable
stack memory is one of the biggest security problems. An execstack error might
in fact be most likely raised by malicious code. Applications are sometimes
coded incorrectly and request this permission. The SELinux Memory Protection
Tests (http://people.redhat.com/drepper/selinux-mem.html) web page explains how
to remove this requirement. If ld-linux.so.2 does not work and you need it to
work, you can configure SELinux temporarily to allow this access until the
application is fixed. Please file a bug report.

Autoriser l'accès:

Sometimes a library is accidentally marked with the execstack flag, if you find
a library with this flag you can clear it with the execstack -c LIBRARY_PATH.
Then retry your application. If the app continues to not work, you can turn the
flag back on with execstack -s LIBRARY_PATH. Otherwise, if you trust
ld-linux.so.2 to run correctly, you can change the context of the executable to
execmem_exec_t. "chcon -t execmem_exec_t '/lib/ld-2.11.so'" You must also change
the default file context files on the system in order to preserve them even on a
full relabel. "semanage fcontext -a -t execmem_exec_t '/lib/ld-2.11.so'"

Commande de correction:

chcon -t execmem_exec_t '/lib/ld-2.11.so'

Informations complémentaires:

Contexte source               unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Contexte cible                unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Objets du contexte            None [ process ]
source                        ld-linux.so.2
Chemin de la source           /lib/ld-2.11.so
Port                          <Inconnu>
Hôte                         (removed)
Paquetages RPM source         glibc-2.11-2
Paquetages RPM cible          
Politique RPM                 selinux-policy-3.6.32-55.fc12
Selinux activé               True
Type de politique             targeted
Mode strict                   Enforcing
Nom du plugin                 allow_execstack
Nom de l'hôte                (removed)
Plateforme                    Linux redhat-rahon 2.6.31.5-127.fc12.i686.PAE #1
                              SMP Sat Nov 7 21:25:57 EST 2009 i686 i686
Compteur d'alertes            3
Première alerte              jeu. 10 déc. 2009 16:41:21 CET
Dernière alerte              jeu. 10 déc. 2009 18:25:44 CET
ID local                      459cf4a6-cc97-4611-adc7-008a12b28abe
Numéros des lignes           

Messages d'audit bruts        

node=redhat-rahon type=AVC msg=audit(1260465944.2:108): avc:  denied  { execstack } for  pid=8732 comm="ld-linux.so.2" scontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=process

node=redhat-rahon type=SYSCALL msg=audit(1260465944.2:108): arch=40000003 syscall=125 success=no exit=-13 a0=bffc9000 a1=1000 a2=1000007 a3=bffc8dd8 items=0 ppid=8730 pid=8732 auid=500 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=1 comm="ld-linux.so.2" exe="/lib/ld-2.11.so" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)



Hash String generated from  selinux-policy-3.6.32-55.fc12,allow_execstack,ld-linux.so.2,unconfined_t,unconfined_t,process,execstack
audit2allow suggests:

#============= unconfined_t ==============
allow unconfined_t self:process execstack;